<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <div id="root"></div>
    <script crossorigin src="https://unpkg.com/react@16/umd/react.development.js"></script>
    <script crossorigin src="https://unpkg.com/react-dom@16/umd/react-dom.development.js"></script>
    <script src="https://unpkg.com/babel-standalone@6/babel.min.js"></script>
    <script type="text/babel">


        // 有一点不好，每次运行得到的ref都不一样
        function App() {
            const inpRef = React.createRef()
            return (
                <div>
                    <input type="text" ref={inpRef} />
                    <button onClick={() => {
                        console.log(inpRef.current.value);
                    }}>获取input的值</button>
                </div>
            )
        }
        ReactDOM.render(<App />, document.getElementById('root'))
    </script>
</body>

</html>